Preparation And Properties Of The Hydrophobic Association Hydrogels Using Gelation As Emulsifier

Hydrogels are polymer with the crosslinking network structure,which can absorb a lot of water but not being dissolved in the aqueous solutions.Because of the feature hydrogels are widely used among the agriculture?industry and biomedicine.Gelatin is a kind of abundant polymer with good biocompatibility and no cytotoxicity.It can be used as the emulsifier in the radical polymerization.At the same time,the gelatin can form gel,so it can form its own network structure made by the hydrogen bond from the active groups on its chain.In our present study,We prepared the hydrophobic association hydrogels through radical micellar polymerization of hydrophilic monomer N-acryloyl-alanine(NAA)and hydrophobic monomer stearyl acrylate(C18)by using the gelatin as emulsifier and ammonium persulfate as initiator.And we researched the influences of filler which could be soluble in water on the properties of the hydrogels.The main works were listed as follows:1.We synthesized the hydrophilic monomer NAA.The amino group on the L-alanine and the acid chloride group on the acryloyl choride reacted to form the monomer NAA which included the amide group and carboxyl.The productivity could reach to 44.8%through controlling the reaction conditions.2.We prepared the hydrophobic association hydrogels successfully and demonstrated the formation of the resulting hydrogels through the fourier transform infrared spectra and DSC,and we saw the microscopic structure through the scanning electric microscope.At the same time,we researched the influences of gelatin content on the structure and properties of hydrogels.With the increasement of gelatin,the swelling ratio and the shape recovery ratio of the hydrophobic association hydrogels decreased,the hydrogels could mostly absorbed 75 times water of its own weight.and it have a recovery ratio of 90%at least.At the same time,with the increasement of gelatin,the tensile strength of the hydrogels increased,and the tensile strength could reach the maximum values of 95KPa.3.We researched the influences of hydrotalcite content on the properties of hydrogels.With the increasement of hydrotalcite,the swelling ratio and the tensile strength of the hydrogels increased,when the mass fraction of the hydrotalcite reached 4%of the NAA,the hydrogels could absorb about 83 times water of its own weight,and the tensile strength of the hydrogels could reach 240KPa.At the same time,with the increasement of hydrotalcite,the shape recovery ratio of the hydrogels remained unchanged and had a shape recovery ratio of 93%.4.We compared the influences of the three kinds of filler(hydrotalcite,clay and graphene oxide)on the properties of the hydrogels.Compared with the blank hydrogel,the swelling ratio of the hydrogels with the hydrotalcite and clay improved,and the hydrogel with clay could absorb 114 times water of its own weight,but the swelling ratio of the hydrogel with graphene oxide decreased.And compared with the blank hydrogel,the shape recovery ratio of the hydrogel with the hydrotalcite remained unchanged,but the shape recovery ratio of the hydrogels with clay and graphene oxide decreased.At the same time,compared with the blank hydrogel,the mechanical property and the hardness of the hydrogels increased,the tensile strength of the hydrogel with clay could reach 280KPa.